tests: Add `guix hash' test.

* guix/scripts/hash.scm (guix-hash)[eof->null]: New procedure.
  Use it to convert the EOF object to the empty bytevector.
* tests/guix-hash.sh: New file.
* Makefile.am (SH_TESTS): Add it.

Makefile.am

@@ -324,6 +324,7 @@ SH_TESTS =					\
   tests/guix-build.sh				\
   tests/guix-download.sh			\
   tests/guix-gc.sh				\
+  tests/guix-hash.sh				\
   tests/guix-package.sh
 
 TESTS = $(SCM_TESTS) $(SH_TESTS)

guix/scripts/hash.scm

@@ -98,6 +98,11 @@ (define (parse-options)
                   (alist-cons 'argument arg result))
                 %default-options))
 
+  (define (eof->null x)
+    (if (eof-object? x)
+        #vu8()
+        x))
+
   (let* ((opts (parse-options))
          (args (filter-map (match-lambda
                             (('argument . value)
@@ -112,7 +117,7 @@ (define (parse-options)
          (lambda ()
            (format #t "~a~%"
                    (call-with-input-file file
-                       (compose fmt sha256 get-bytevector-all))))
+                     (compose fmt sha256 eof->null get-bytevector-all))))
          (lambda args
            (leave (_ "~a~%")
                   (strerror (system-error-errno args))))))

tests/guix-hash.sh

@@ -0,0 +1,28 @@
+# GNU Guix --- Functional package management for GNU
+# Copyright © 2013 Ludovic Courtès <ludo@gnu.org>
+#
+# This file is part of GNU Guix.
+#
+# GNU Guix is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or (at
+# your option) any later version.
+#
+# GNU Guix is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+#
+# Test the `guix hash' command-line utility.
+#
+
+guix hash --version
+
+test `guix hash /dev/null` = 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
+test `guix hash -f nix-base32 /dev/null` = 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
+test `guix hash -f hex /dev/null` = e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
+test `guix hash -f base32 /dev/null` = 4oymiquy7qobjgx36tejs35zeqt24qpemsnzgtfeswmrw6csxbkq